Which of following statements about testing software with data is (are) true　　Ⅰ. The primary purpose of such testing is to find errors.　　Ⅱ. Such testing can demonstrate the existence of errors but can not demonstrate the absence of errors.

A．Neither

B．Ⅰ only

C．Ⅱ only

D．Ⅰ and Ⅱ